![]() ![]() For example if the red dot is at the –4 mark, then your audio is four frames BEFORE the video. Place the playhead there and look at the video wherever the red speaker dot is, indicates how many frames you need to adjust. Load the recorded clip into an NLE and look for the BEEP on the audio waveform.It's helpful to run it for more than just a couple of beeps so you can verify there is no variance from the beginning to the end of the clip. Shoot video of the test at least several seconds, but 30 should be more than enough.Ensure that the microphone is in (close to) the same position it will be for the production, that the microphone can clearly pick up the BEEP from sync test video, and that you can clearly see the sync test video on camera. Position your laptop/tablet where the talent will be, play back the downloaded sync test (full screen and full volume is best), and point your HDMI camera at the screen.It's critical that you use the matching frame rate to your production, or this won't work! Download the video(s) for the appropriate frame rate to a laptop or tablet (the bigger the screen, the easier it will be to see this).I made a video that explains this… check it out here. These custom videos allow you to measure the delay so you can program it into your hardware. If you're using a professional sound mixing board, the board can typically program a delay into it in milliseconds, so the audio actually arrives to your switcher / streaming hardware at the same time as the video. Devices like the ATEM Mini Pro have the ability to program in a delay for the audio, so is in sync with video. However when using an HDMI camera in a live production situation, if you're mixing video from the camera and audio from another source, the audio will generally be in real time while the video will not, resulting in an audio/video mismatch. When recording video, this is irrelevant. Why you need theseĪll HDMI cameras have a slight delay between realtime and what's actually output over HDMI this is simply inherent in HDMI processing and is unavoidable. These are my own custom audio sync tests, provided for you to freely download at all common frame rates of 23.98, 24, 25, 29.97, 50 and 59.94 fps. Apple has been notified of this problem, and replacement files are on the servers. The new exports are all HEVC, which are (verified!) perfectly in sync. The master files were perfect - the H.264 were all shifted by a frame (and in some cases, more!). It turns out this is, as far as I can tell, a bug in Apple Compressor. This is horrendous and I apologize profusely. We’ll take a separate look at the ways to fix TV sound desync.UPDATE: In March 2021, it was brought to my attention that the downloaded files were actually OUT OF SYNC. But if you only need to sync up video files, then that can be done in a media player.įinally, audio (or video) delay can appear in an HD-home-cinema kind of setup, due to the sheer volume of data that UHD and lossless sound require. If you need to eliminate sound delay in games or streamed media, wired headphones or speakers are the only way. It’s getting smaller on newer devices, but it’s not perfect yet. Compression and decompression create a noticeable delay. But its bandwidth is narrow, less than a cable, so it requires audio to be compressed. Bluetooth is about as fast as cables, which is why it works without delay for keyboards, mice, and gamepads. Also, sometimes video and audio tracks have different durations and play at different speeds, which makes perfect sync impossible, especially when the media is one or more hours long.īluetooth audio hardware is another possible desync source. Obviously, it’s not as easy when you’re viewing a desynchronized stream on the internet. This can be fixed in most modern media players by adjusting the audio delay. In this case, the creator of the video didn’t bother to synchronize the tracks. ![]() Generally, ways to synchronize audio and video are the same for all for them, but it’s useful knowledge either way.įirst of all, it could be a problem with the video you’re watching. There are three common causes for audio sync problems. ![]()
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